First Chemical Synthesis, Aggregation Behavior and Cholesterol Solubilization Properties of Pythocholic Acid and 16α‐Hydroxycholic Acid

The first chemical synthesis of pythocholic acid, a major component of python's bile, and 3α,7α,12α,16α‐tetrahydroxy‐5β‐cholan‐24‐oic acid (16α‐hydroxycholic acid), a minor component in Shoebill stork's bile, was achieved starting from readily available cholic acid in overall yields of 5 % and 5.5 %, respectively, through a common intermediate. A biomimetic template‐directed remote functionalization strategy was utilized to selectively functionalize C‐16 of the steroid skeleton. This synthesis involves a series of regio and chemoselective transformations. Pythocholic acid showed unusually low critical micellar concentration (CMC) with high cholesterol solubilization ability. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)